백서 표피 분화에 관한 전자현미경적 연구

정병훈,이법이,정호삼,이규식,Chung, Byung-Hoon,Lee, Beob-Yi,Chung, Ho-Sam,Lee, Kyu-Sik 한국현미경학회 1991 Applied microscopy Vol.21 No.2

The authors studied the morphological distinctions of each of the epidermal layers and the time of appearance of the keratohyalin granules and tonofilaments by the processing of development. The skins were obtained from fetal rats at the age of 14th, 16th, 17th, 18th, 19th and 20th day of gestation, of 1st and 3rd day of neonatal life and of 4th week after birth. The specimens were staind with uranyl acetate and lead citrate. The results obtained were as follows. 1. On the 16th-gestation day, the intermediate layer which contained numerous ${\alpha}-and\;{\beta}$-glycogen particles was appeared, and hemidesmosomes and desmosome were observed as well. 2. Tonofilaments were first observed on the 17th gestation day. 3. Above-mentioned intermediate layer was differentiated into the granular layer and the spinous layer on the 18th-gestation day. Keratohyaline granules were appeared in association with the ribosomes and the tonofilaments and the compound granules were lipoid granules which were surrounded by ribosomes at the periphery. 4. Ultimately, keratinization began to take place from the 20th-gestation day. At the age of 4th week, the thickeness of epidermis and the amount of keratohyaline granule and tonofibrils were decreased. It is consequently suggested that in the differentiation process of the rat epidermis, keratinization begins after formation of hemidesmosomes and desmosomes, from which the tonofilaments are formed and after keratohyaline granules are formed. Therefore appearance of the keratohyaline granules and formation of the tonofilament appears to have a close relations with the keratinization process of the rat epidermis.

과학과 비과학의 구획의 문제 (Ⅰ)

정병훈(Chung, Byung Hoon) 경상대학교 사회과학연구원(사회과학연구) 1984 사회과학연구 Vol.1 No.-

Science Education and Teacher Education in Germany

정병훈(Byung Hoon Chung),(Cristine Seybel) 한국과학교육학회 1995 한국과학교육학회 학술발표 및 세미나집 Vol.1995 No.2

전류신호를 이용한 유도전동기의 회전자봉 결함검출에 관한 연구

정병훈(Byung-Hoon Chung),신대철(Dae-Chul Shin) 한국소음진동공학회 2002 한국소음진동공학회 논문집 Vol.12 No.4

과학과 비과학의 구획의 문제 (Ⅱ)

정병훈(Chung, Byung-Hoon) 경상대학교 사회과학연구원(사회과학연구) 1985 사회과학연구 Vol.2 No.-

차량용 공조 팬의 소음 저감에 대한 실험적 연구

이진갑(Lee, Jin-Kab),정병훈(Chung, Byung-Hoon) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.1

본 논문은 철도 차량에 사용하는 라인 플로우 팬의 소음 저감을 위해 소음원을 규명하여 저감하는 실험적인 연구이다. 라인 플로우 팬의 소음은 공기 유동에 의한 난류성 유동 및 랜덤성 소음, 블레이드 통과 주파수(681Hz)의 소음, 모터 회전에 의한 로터의 불균형(28.4Hz)의 구조물 진동에 의한 소음 등 여러 요인에 의해 발생된다. 각각의 소 음원에 대해 대책을 수립하여 하우징 가이드 각도 및 거리 조정, 유동 통로의 형상 변경, 로터 밸런싱을 통해 총 5.7dB(A)의 소음을 저감하였다. This paper is the experimental study to investigate the noise sources location in order to reduce the noise level of line flow fan for the air conditioner in the subway car . The noise of line flow fan is caused by various factors such as the turbulence by air flow, random noise, noise of blade passing frequence(681Hz) and noise due to structural vibration of rotor unbalance(28.4Hz) by motor revolution. By performing the noise reduction on each sound source, the noise level is decreased as much as 5.7dB(A) through the controls of housing guide angle and distance, the configuration changes of flow passage shape and rotor balancing.

ARTIS?? PL E 인공수정체를 이용한 백내장수술의 임상적 결과

박서연(Ella Seo Yeon Park),정병훈(Byung Hoon Chung),전익현(Ikhyun Jun),김태임(Tae-im Kim),서경률(Kyoung Yul Seo),김응권(Eung Kweon Kim) 대한안과학회 2022 대한안과학회지 Vol.63 No.2

목적: 백내장수술시 ARTIS?? PL E (Cristalens Industrie, Lannion, France) 인공수정체와 Tecnis?? ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA) 인공수정체를 삽입한 환자들의 임상 결과를 비교하였다. 대상과 방법: 동일한 술자로부터 백내장초음파유화술을 받고 ARTIS?? PL E를 삽입한 33안(A군)과 Tecnis?? ZCB00을 삽입한 45안(B군)의 의무기록을 후향적으로 분석하였다. 수술 후 1, 3개월 되는 시점에서의 최대교정시력, 굴절력 및 고위수차를 수술 전과 비교하였다. 결과: 수술 전 최대교정시력은 A군과 B군 간 유의한 차이는 없었다(p=0.494). 수술 후 최대교정시력은 각각 logMAR 0.01 ± 0.05, 0.01 ± 0.04로 두 군 모두 유의미한 호전을 보였으나(p<0.001), 두 군 간 유의한 차이는 없었다(p=0.289, p=0.471). 수술 후 1, 3개월 경과한 시점에서 전체, 구면, 코마수차는 모두 수술 전과 비교하여 유의하게 감소하였다(p<0.05). 두 집단 모두 수술 1, 3개월 후 목표 굴절력 ± 0.50 diopters 이내가 확인되어 예측도 면에서 유의한 차이는 없었다(p=0.390, p=0.959). 또한, 각 그룹에서 수술 후 1, 3개월째 굴절력에는 통계학적으로 유의한 변화는 없었다(p=0.482, p=0.372). 결론: ARTIS?? PL E 인공수정체를 이용한 백내장수술 후 최대교정시력의 유의미한 향상을 보였으며, 수술 후 시력 변화 및 고위수차에서 기존에 임상효과가 검증되었던 Tecnis?? ZCB00과 대등한 결과를 보였다. Purpose: To compare the clinical outcomes of cataract surgery using the ARTIS?? PL E (Cristalens Industrie, Lannion, France) intraocular lens (IOL) and conventional Tecnis?? ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA) IOL. Methods: This retrospective study examined patients who underwent in-the-bag implantation of either an ARTIS?? PL E (33 eyes, group A) or Tecnis?? ZCB00 (45 eyes, group B) IOL after phacoemulsification performed by a single surgeon. Best-corrected visual acuity (BCVA), spherical equivalent, and higher-order aberrations (HOA) were measured 1 and 3 months after cataract surgery. Results: Preoperative BCVA did not differ significantly in groups A and B. Postoperative BCVA at 1 and 3 months improved significantly (p < 0.001) in both groups compared to preoperative baseline BCVA. At 1 and 3 months postoperatively, total HOA, spherical aberration, and coma were significantly lower compared to the preoperative baseline HOA (p < 0.05) in both groups. However, there were no significant differences in the trefoil values 1 and 3 months postoperatively compared to the preoperative baseline in both groups. The absolute refractive error 3 months postoperatively was 0.27 ± 0.20 (group A) and 0.28 ± 0.20 (group B), both within ± 0.50 diopters of the targeted goal diopter; there were no significant differences in the accuracy or predictability of the IOL power calculation in both groups (p = 0.390, p = 0.959). The absolute refractive error 1 and 3 months postoperatively did not differ significantly; there were no significant differences in the stability of both IOLs (p = 0.482, p = 0.372). Conclusions: Conventional cataract surgery using the ARTIS?? PL E IOL significantly increased the BCVA, while obtaining comparable clinical results to the verified Tecnis?? ZCB00 IOL in postoperative visual acuity and HOA.

알루미늄합금과아연도금강판의이종겹치기마찰교반접합에서기계적성질에미치는ToolGeometry의영향

김남규 ( Nam Kyu Kim ),김병철 ( Byung Chul Kim ),강정윤 ( Chung Yun Kang ),송상우 ( Sang Woo Song ),정병훈 ( Byung Hoon Jung ) 대한금속재료학회 ( 구 대한금속학회 ) 2010 대한금속·재료학회지 Vol.48 No.6

The specific motivation for joining an Al alloy and Zn-coated steel arises from the need to save fuel consumption by weight reduction and to enhance the durability of vehicle structures in the automobile industry. In this study, the lap joining A6K31 Al alloy (top) and SGARC340 Zn-coated steel (bottom) sheets with a thickness of 1.0 mm and 0.8 mm, respectively, was carried out using the friction stir weld (FSW) technique. The probe of a tool did not contact the surface of the lower Zn-coated steel sheet. The friction stir welding was carried out at rotation speeds of 1500 rpm and travel speeds of 80~200 mm/min. The effects of tool geometry and welding speed on the mechanical properties and the structure of a joint were investigated. The tensile properties for the joints welded with a larger tool were better than those for the joints done with a smaller tool. A good correlation between the tensile load and area of the welded region were observed. The bond strength using a larger tool (M4 and M3) decreased with an increase in welding speed. Most fractures occurred along the interface between the Zn-coated steel and the Al alloy. However, in certain conditions with a lower welding speed, fractures occurred at the A6K31 Al alloy.

초등과학영재를 위한 원격교수 학습 자료 개발 및 적용2

박종석(Jong-Seok Park),오원근(Won-Kun Oh),박종욱(Joung-Wook Park),정병훈(Byung-Hoon Chung) 한국영재학회 2003 영재교육연구 Vol.13 No.2

본 연구에서는 탐구 과정기술과 사고력을 중시하는 초등학교 과학과목의 특성을 고려하여 개발된 원격교육모형에 적용할 수 있는 학습 자료를 개발하고, 원격교수학습의 보고서를 통해 나타난 학생들의 특성을 조사하였다. 학생들은 보고서 작성을 위해 다양한 실험 방법들을 고안하는 과정에서 관찰 태도나 과학적 사고력을 신장시키는 계기를 가졌다. 이 같은 결과는 원격교육의 수업 모형이 학생들 간의 상호 작용과 그것을 종합화 할 수 있는 보고서 및 평가 등의 구성 요소들로 이루어졌기 때문에 가능할 수 있었다. 그러나 원격교육에서는 교사들이 학생들을 직접 관리 또는 감독하지 못하기 때문에 학생들의 특성을 바람직한 방향으로 유도하기가 곤란한 점도 없지 않아 있다는 것을 인정하여야 한다. 예를 들어, 보고서 작성의 형식에 대해 개별적인 평가를 해 주어도 학생들은 자신들이 가지고 있는 생각의 틀을 고수하는 점을 볼 수 있었다. In this study, learning materials that can be applied for web-based distant learning model were developed based on the characteristics of elementary school science in which investigation skills and thinking ability are considered to be important. And the effect of students' activity in a reports on student's investigating and thinking ability was investigated. While designing diverse experimental procedures, the students had an opportunity to improve their observation attitude and way of scientific thinking. Such improvement was possible, only because the present web-based distant learning model consists of requiring an interaction between the students and a report and evaluation system which can put together such effort. Still, it was acknowledged that, as being in lack of teacher's direct support and supervision, the present web-based distant learning model might be somewhat ineffective in guiding the students in accordance with their own characteristics. For example, the students had a tendency to maintain their basic idea and style even when their reports are individually examined and corrected in terms of the format of the report.

초등과학영재를 위한 원격교수 학습 자료 개발 및 적용1

박종석(Jong-Seok Park),오원근(Won-Kun Oh),박종욱(Jong-Wook Park),정병훈(Byung-Hoon Chung) 한국영재학회 2003 영재교육연구 Vol.13 No.2

본 연구에서는 탐구 과정기술과 사고력을 중시하는 초등학교 과학과목의 특성을 고려하여 개발된 원격교육모형에 적용할 수 있는 학습 자료를 개발하고, 원격교수학습의 토론방 활동을 통해 나타난 학생들의 특성을 조사하였다. 탐구적 사고력을 향상시킬 수 있는 자료를 개발하여 원격교육을 실시한 결과 학생들은 토론방에서 활발한 토론을 통해서 다양한 사고와 실험 방법 등을 고안하고 수행하는 태도들을 나타냈다. 특히 주어진 과제들이 주변 환경 속에서 찾을 수 있는 실험 도구들을 사용하도록 구성되었기 때문에 web 환경에서 이루어지는 원격교육이 단점을 극복하면서 학생들의 탐구적 활동을 자극 하였다. In this study, learning materials that can be applied for web-based distant learning model were developed based on the characteristics of elementary school science in which investigation skills and thinking ability are considered to be important. And the effect of students' activity in a discussion room on student's investigating and thinking ability was investigated. Through very active on-line discussion, students showed their ability to come up with new ideas and to design and implement diverse experimental methods. Especially, since all of the study tasks given to the students were aimed to utilize experimental means and tools that are so common in everyday life, shortfalls that might reside in the web-based distant learning program could be overcome and students' investigative activity might be stimulated.